This invention relates in general to sublimation dye thermal and inkjet printing systems and, more specifically, to thermal printers for photographic image printing. More particularly, the invention relates to a method and system for removing paper trimmings that are created internally in thermal printer systems and that would otherwise interfere with printing.
Without limiting the scope of the invention, its background is described in connection with thermal printers, such as the Kodak Photo Printer 4720 (Sidewinder 2 Thermal Printer), as an example.
Thermal and inkjet printing systems are commonly used for the production of text and graphic images for home, office and commercial applications. Such printing systems include receiver media for printing, such as paper, which can be supplied either from a stack or several stacks of pre-cut receiver media, or can be cut from a receiver media supply roll. After the printing cycle, an internal cutter assembly is utilized to trim printed receiver media to size and/or to cut non-printed areas from the printed receiver media. These paper trimmings (or xe2x80x9cchadxe2x80x9d) are intended to fall from the cutter assembly and down on a paper tray having a tray cover. The tray and tray cover are commonly found in the device directly beneath the cutter assembly. In most cases, the tray cover is designed to cause the trimmings to slide into a temporary holding area. The trimmings are then removed from the temporary holding area by an operator at the same time the supply of receiver media is replenished.
Frequently, however, static charges build up in the area due to the act of cutting the receiver media and causing it to travel through a designated area. If not static, other factors and/or conditions, such as chad size, chad position, or humidity, for example, may exist. Whether individually or in combination, these factors and conditions have been found to cause paper trimmings to stick on the ray cover, and prohibiting their removal away from the cutter assembly. In some instances, the chad will pile up to the point of causing interference with the paper path or creating paperjams.
Accordingly, a need exists for a printer system with integral means for reliably storing trimmings produced during the printing and cutting of receiver media. A need also exists for a system which would prevent paper trimmings from interfering with the function of the printer. As such, a means of controlling the build-up of paper trimmings resulting from the cutting of printed receiver media would provide numerous advantages.
The present invention provides a system and method for moving paper trimmings, or chad, that are created internally in thermal printers that otherwise could interfere with printing. With the present invention, chad build-up is eliminated and the possibility for paper jams is decreased.
Accordingly, disclosed in one embodiment is a printer system comprising a roller system for directing trimmings resulting from the cutting of printed receiver media into a holding area. In a preferred embodiment of the present invention, the roller system includes a roller configured to translate the paper trimmings away from the cutter assembly. The roller can be configured to rotate intermittently, thus operating in connection with the actions of a pick roller.
The roller system also comprises a tray configured to hold a supply of receiver media for printing. The supply of receiver media can include a plurality of receiver media sheets, or a receiver media supply roll, for example. Positioned over the tray is a tray cover having at least one aperture for receiving a roller or drive belt. In one embodiment, the tray cover is in a sloped position, so that it sits 15 degrees from its X-axis position. The tray cover further includes a temporary storage cavity integral to the tray cover. As such, the temporary storage cavity defines a holding area for trimmings resulting from the cutting of printed receiver media. Thus, if the tray is adapted to hold 100 sheets of paper, then the holding area of the temporary storage cavity is adapted to hold trimmings from 100 sheets of paper. As such, the volume of the holding area and the number of sheets of paper are proportional.
The printer system also comprises a receiver media feeder for drawing receiver media from the supply of receiver media unto a receiver media path. In one embodiment, the receiver media feeder is a pick roller adapted to come in contact with the supply of receiver media in the tray. The pick roller is configured to rotate and direct receiver media along a receiver media path.
The printer system further comprises a printhead for printing images on the receiver media from the supply of receiver media and a cutter assembly for trimming the printed receiver media to size. In one embodiment, the printer system includes means for retaining at least one edge of the receiver media during the printing process. Typically, the area retained will remain blank, or free of printed images. As such, those non-printed areas on the printed receiver media will require cutting. The cutter assembly further includes first and second rollers, which are configured to direct printed receiver media out via the exit pathway after cutting. In another embodiment, a third roller is operably engaged with the second roller and positioned above the temporary storage cavity in order to eliminate the build-up of receiver media trimmings at the edge of the holding area.
According to another embodiment, disclosed is a method of controlling the build-up of trimmings, or chad, resulting from the cutting of printed receiver media for a printer system including an internal supply of receiver media and means for printing images on the receiver media. Initially, receiver media is drawn from a tray and directed to a receiver media path. Concurrently, a roller is caused to translate trimmings from previous cutter activity into a temporary holding area. While the trimmings are being directed to their designated area, the receiver media drawn from the tray is positioned for printing. That is, the receiver media is retained from at least one edge in position during the printing process. Once printing has terminated, non-printed areas on the receiver media are identified, such as the area where the receiver media was retained. Those areas are then trimmed so as to cut the printed receiver media to size.
The method further comprises the step of causing the cut printed receiver media to exit via an exit pathway. Concurrently, a roller is caused to tumble stacks of trimmings, which may have formed on the edge of the holding area, into the holding area. The motion of the roller is accomplished by a friction interface with rollers within the cutter assembly, or through belt drives or direct gearing.
In this way, the present invention provides a printer system with integral means for reliably removing chad produced during the printing and cutting of receiver media.
A technical advantage of the invention is a printer system which is designed to prevent paper trimmings from interfering with the function of the printer. Larger printing cycles can be obtained without maintenance and with less interruption. Therefore, the user benefits from reduced maintenance costs.